Since the late eighteenth century, doctors connected with European mental institutions in South Asia were trained in western medicine and its diagnostic categories. Following the move towards standardised categorisations of mental illnesses in Europe and North America during the early twentieth century, uniformity of classification schemes was enforced in colonial institutions in South Asia, too. The classifications were based on British blueprints with but few modifications that allowed for perceived cultural syndromes, such as cannabis-induced psychosis and dhat syndrome. Despite apparent standardisation of nosology, diagnostic practice varied considerably in individual institutions. The lecture focuses on melancholia, circular insanity and depression. It highlights the multiple conceptualisations of these categories across as well as between cultures and localities, and identifies the diverse influence on particular psychiatrists in South Asia of German, French, American and British diagnostic styles and preferences.